Try drawing / erasing
EH is the length of entire line.
So you have EH = 9
You have FH = 6 so let's subtract:
EH - FH will leave beside EF
And EH - FH = 9 - 6 = 3
So EF = 3
We need EG so that means we need FG to be added to EF. We already have FG
FG = 4 so we have EF + FG = EG
and EF + FG = 3 + 4 = 7
Final answer: 7
